We have done probably a dozen AD to S10 swaps, a Dakota, several 71 or 72 Chevy pickup (disc brake) crossmembers(UGLY), a 74 Cadillac complete chassis (shorted and narrowed) with a 500 Cadillac engine all in a 51 GMC, a drag truck 50 3w cab with a complete tubing frame and 8 point roll cage, probably close to 50 Nova, Camaro/Firebird (bad idea on the latter two), a dozen Pacer IFS, and won't guess on how many MII's including back in the days we had to cut them out of a Pinto or Mustang. Have pictures of most and also have for sale a 52 frame with a Pacer IFS and a Lincoln Mark 8 IRS if you want to go exotic. With that said I would keep the original frame with a GOOD brand MII kit and a coil over rear for a modern truck APPROXIMATE ride and feel. Still will have a lot of wind noise above 55mph or so. With coil overs on all four corners you can set or change the height and ride easily and much cheaper than with any other set up. You will find the cab, bed, core support, bumpers, etc will bolt to the original frame a tiny bit easier than anything else.
